Introduction to Probability

Probability is the study of the likelihood of an event happening. Simply, it is how likely something is to happen. Probability plays a role in all activities, directly or indirectly. For example, we may say that tomorrow will probably be sunny because most of the days we have observed were sunny days.
Many events cannot be predicted with certainty. When people are unsure about the outcome of an event, they can talk about the probabilities of specific outcomes—their likelihood. The analysis of events that are governed by probability is known as statistics.
To understand probability, the best example is flipping a coin. There are two possible outcomes: tails (T) and heads (H). What is the probability of the coin landing on Tails or Head? The probability of the coin landing T is ½, and the probability of the coin landing H is ½. Another example that can help you understand probability is throwing a dice. When a die is thrown, there are six possible outcomes. The probability of any one of them is 1/6.
In general, the probability of an event = (Number of ways it can occur) / (total number of outcomes).
These lessons on probability often include the following topics: the probability of events, samples in probability, theoretical probability, probability problems, experimental probability, tree diagrams, independent events, mutually exclusive events, dependent events, permutations, factorial, combinations, probability, probability in statistics, and combinatorics.